/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.streaming.api.operators;

import org.apache.flink.runtime.checkpoint.OperatorSubtaskState;
import org.apache.flink.runtime.concurrent.FutureUtils;
import org.apache.flink.runtime.state.KeyedStateHandle;
import org.apache.flink.runtime.state.OperatorStateHandle;
import org.apache.flink.runtime.state.SnapshotResult;

import javax.annotation.Nonnull;

import java.util.concurrent.ExecutionException;

/**
 * This class finalizes {@link OperatorSnapshotFutures}. Each object is created with a {@link OperatorSnapshotFutures}
 * that is executed. The object can then deliver the results from the execution as {@link OperatorSubtaskState}.
 */
public class OperatorSnapshotFinalizer {

	/** Primary replica of the operator subtask state for report to JM. */
	private final OperatorSubtaskState jobManagerOwnedState;

	/** Secondary replica of the operator subtask state for faster, local recovery on TM. */
	private final OperatorSubtaskState taskLocalState;

	public OperatorSnapshotFinalizer(
		@Nonnull OperatorSnapshotFutures snapshotFutures) throws ExecutionException, InterruptedException {

		SnapshotResult<KeyedStateHandle> keyedManaged =
			FutureUtils.runIfNotDoneAndGet(snapshotFutures.getKeyedStateManagedFuture());

		SnapshotResult<KeyedStateHandle> keyedRaw =
			FutureUtils.runIfNotDoneAndGet(snapshotFutures.getKeyedStateRawFuture());

		SnapshotResult<OperatorStateHandle> operatorManaged =
			FutureUtils.runIfNotDoneAndGet(snapshotFutures.getOperatorStateManagedFuture());

		SnapshotResult<OperatorStateHandle> operatorRaw =
			FutureUtils.runIfNotDoneAndGet(snapshotFutures.getOperatorStateRawFuture());

		jobManagerOwnedState = new OperatorSubtaskState(
			operatorManaged.getJobManagerOwnedSnapshot(),
			operatorRaw.getJobManagerOwnedSnapshot(),
			keyedManaged.getJobManagerOwnedSnapshot(),
			keyedRaw.getJobManagerOwnedSnapshot()
		);

		taskLocalState = new OperatorSubtaskState(
			operatorManaged.getTaskLocalSnapshot(),
			operatorRaw.getTaskLocalSnapshot(),
			keyedManaged.getTaskLocalSnapshot(),
			keyedRaw.getTaskLocalSnapshot()
		);
	}

	public OperatorSubtaskState getTaskLocalState() {
		return taskLocalState;
	}

	public OperatorSubtaskState getJobManagerOwnedState() {
		return jobManagerOwnedState;
	}
}
